Auto merge of #29581 - gereeter:unwrap-defmap-refcell, r=nrc

This is basically a more conservative recreation of #24096.

src/librustc/middle/cfg/construct.rs

@@ -472,7 +472,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                     let guard_exit = self.expr(&**guard, guard_start);
 
                     let this_has_bindings = pat_util::pat_contains_bindings_or_wild(
-                        &self.tcx.def_map, &**pat);
+                        &self.tcx.def_map.borrow(), &**pat);
 
                     // If both this pattern and the previous pattern
                     // were free of bindings, they must consist only

src/librustc/middle/check_match.rs

@@ -702,7 +702,7 @@ fn is_useful(cx: &MatchCheckCtxt,
 
             Some(constructor) => {
                 let matrix = rows.iter().filter_map(|r| {
-                    if pat_is_binding_or_wild(&cx.tcx.def_map, raw_pat(r[0])) {
+                    if pat_is_binding_or_wild(&cx.tcx.def_map.borrow(), raw_pat(r[0])) {
                         Some(r[1..].to_vec())
                     } else {
                         None
@@ -1073,7 +1073,7 @@ fn check_legality_of_move_bindings(cx: &MatchCheckCtxt,
         // check legality of moving out of the enum
 
         // x @ Foo(..) is legal, but x @ Foo(y) isn't.
-        if sub.map_or(false, |p| pat_contains_bindings(def_map, &*p)) {
+        if sub.map_or(false, |p| pat_contains_bindings(&def_map.borrow(), &*p)) {
             span_err!(cx.tcx.sess, p.span, E0007, "cannot bind by-move with sub-bindings");
         } else if has_guard {
             span_err!(cx.tcx.sess, p.span, E0008, "cannot bind by-move into a pattern guard");
@@ -1086,7 +1086,7 @@ fn check_legality_of_move_bindings(cx: &MatchCheckCtxt,
 
     for pat in pats {
         front_util::walk_pat(&**pat, |p| {
-            if pat_is_binding(def_map, &*p) {
+            if pat_is_binding(&def_map.borrow(), &*p) {
                 match p.node {
                     hir::PatIdent(hir::BindByValue(_), _, ref sub) => {
                         let pat_ty = tcx.node_id_to_type(p.id);
@@ -1181,7 +1181,7 @@ struct AtBindingPatternVisitor<'a, 'b:'a, 'tcx:'b> {
 
 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for AtBindingPatternVisitor<'a, 'b, 'tcx> {
     fn visit_pat(&mut self, pat: &Pat) {
-        if !self.bindings_allowed && pat_is_binding(&self.cx.tcx.def_map, pat) {
+        if !self.bindings_allowed && pat_is_binding(&self.cx.tcx.def_map.borrow(), pat) {
             span_err!(self.cx.tcx.sess, pat.span, E0303,
                                       "pattern bindings are not allowed \
                                        after an `@`");

src/librustc/middle/check_static_recursion.rs

@@ -237,7 +237,7 @@ impl<'a, 'ast: 'a> Visitor<'ast> for CheckItemRecursionVisitor<'a, 'ast> {
     fn visit_expr(&mut self, e: &'ast hir::Expr) {
         match e.node {
             hir::ExprPath(..) => {
-                match self.def_map.borrow().get(&e.id).map(|d| d.base_def) {
+                match self.def_map.get(&e.id).map(|d| d.base_def) {
                     Some(DefStatic(def_id, _)) |
                     Some(DefAssociatedConst(def_id)) |
                     Some(DefConst(def_id)) => {

src/librustc/middle/dead.rs

@@ -250,7 +250,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for MarkSymbolVisitor<'a, 'tcx> {
     fn visit_arm(&mut self, arm: &hir::Arm) {
         if arm.pats.len() == 1 {
             let pat = &*arm.pats[0];
-            let variants = pat_util::necessary_variants(&self.tcx.def_map, pat);
+            let variants = pat_util::necessary_variants(&self.tcx.def_map.borrow(), pat);
 
             // Inside the body, ignore constructions of variants
             // necessary for the pattern to match. Those construction sites
@@ -270,7 +270,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for MarkSymbolVisitor<'a, 'tcx> {
             hir::PatStruct(_, ref fields, _) => {
                 self.handle_field_pattern_match(pat, fields);
             }
-            _ if pat_util::pat_is_const(def_map, pat) => {
+            _ if pat_util::pat_is_const(&def_map.borrow(), pat) => {
                 // it might be the only use of a const
                 self.lookup_and_handle_definition(&pat.id)
             }

src/librustc/middle/def.rs

@@ -17,8 +17,6 @@ use util::nodemap::NodeMap;
 use syntax::ast;
 use rustc_front::hir;
 
-use std::cell::RefCell;
-
 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Def {
     DefFn(DefId, bool /* is_ctor */),
@@ -103,7 +101,7 @@ impl PathResolution {
 }
 
 // Definition mapping
-pub type DefMap = RefCell<NodeMap<PathResolution>>;
+pub type DefMap = NodeMap<PathResolution>;
 // This is the replacement export map. It maps a module to all of the exports
 // within.
 pub type ExportMap = NodeMap<Vec<Export>>;

src/librustc/middle/expr_use_visitor.rs

@@ -934,7 +934,7 @@ impl<'d,'t,'a,'tcx> ExprUseVisitor<'d,'t,'a,'tcx> {
         return_if_err!(self.mc.cat_pattern(cmt_discr, pat, |_mc, cmt_pat, pat| {
             let tcx = self.tcx();
             let def_map = &self.tcx().def_map;
-            if pat_util::pat_is_binding(def_map, pat) {
+            if pat_util::pat_is_binding(&def_map.borrow(), pat) {
                 match pat.node {
                     hir::PatIdent(hir::BindByRef(_), _, _) =>
                         mode.lub(BorrowingMatch),
@@ -969,7 +969,7 @@ impl<'d,'t,'a,'tcx> ExprUseVisitor<'d,'t,'a,'tcx> {
         let def_map = &self.tcx().def_map;
         let delegate = &mut self.delegate;
         return_if_err!(mc.cat_pattern(cmt_discr.clone(), pat, |mc, cmt_pat, pat| {
-            if pat_util::pat_is_binding(def_map, pat) {
+            if pat_util::pat_is_binding(&def_map.borrow(), pat) {
                 let tcx = typer.tcx;
 
                 debug!("binding cmt_pat={:?} pat={:?} match_mode={:?}",

src/librustc/middle/pat_util.rs

@@ -18,11 +18,13 @@ use rustc_front::hir;
 use rustc_front::util::walk_pat;
 use syntax::codemap::{respan, Span, Spanned, DUMMY_SP};
 
+use std::cell::RefCell;
+
 pub type PatIdMap = FnvHashMap<ast::Name, ast::NodeId>;
 
 // This is used because same-named variables in alternative patterns need to
 // use the NodeId of their namesake in the first pattern.
-pub fn pat_id_map(dm: &DefMap, pat: &hir::Pat) -> PatIdMap {
+pub fn pat_id_map(dm: &RefCell<DefMap>, pat: &hir::Pat) -> PatIdMap {
     let mut map = FnvHashMap();
     pat_bindings(dm, pat, |_bm, p_id, _s, path1| {
         map.insert(path1.node, p_id);
@@ -36,7 +38,7 @@ pub fn pat_is_refutable(dm: &DefMap, pat: &hir::Pat) -> bool {
         hir::PatEnum(_, _) |
         hir::PatIdent(_, _, None) |
         hir::PatStruct(..) => {
-            match dm.borrow().get(&pat.id).map(|d| d.full_def()) {
+            match dm.get(&pat.id).map(|d| d.full_def()) {
                 Some(DefVariant(..)) => true,
                 _ => false
             }
@@ -51,7 +53,7 @@ pub fn pat_is_variant_or_struct(dm: &DefMap, pat: &hir::Pat) -> bool {
         hir::PatEnum(_, _) |
         hir::PatIdent(_, _, None) |
         hir::PatStruct(..) => {
-            match dm.borrow().get(&pat.id).map(|d| d.full_def()) {
+            match dm.get(&pat.id).map(|d| d.full_def()) {
                 Some(DefVariant(..)) | Some(DefStruct(..)) => true,
                 _ => false
             }
@@ -63,7 +65,7 @@ pub fn pat_is_variant_or_struct(dm: &DefMap, pat: &hir::Pat) -> bool {
 pub fn pat_is_const(dm: &DefMap, pat: &hir::Pat) -> bool {
     match pat.node {
         hir::PatIdent(_, _, None) | hir::PatEnum(..) | hir::PatQPath(..) => {
-            match dm.borrow().get(&pat.id).map(|d| d.full_def()) {
+            match dm.get(&pat.id).map(|d| d.full_def()) {
                 Some(DefConst(..)) | Some(DefAssociatedConst(..)) => true,
                 _ => false
             }
@@ -77,7 +79,7 @@ pub fn pat_is_const(dm: &DefMap, pat: &hir::Pat) -> bool {
 pub fn pat_is_resolved_const(dm: &DefMap, pat: &hir::Pat) -> bool {
     match pat.node {
         hir::PatIdent(_, _, None) | hir::PatEnum(..) | hir::PatQPath(..) => {
-            match dm.borrow().get(&pat.id)
+            match dm.get(&pat.id)
                     .and_then(|d| if d.depth == 0 { Some(d.base_def) }
                                   else { None } ) {
                 Some(DefConst(..)) | Some(DefAssociatedConst(..)) => true,
@@ -108,12 +110,12 @@ pub fn pat_is_binding_or_wild(dm: &DefMap, pat: &hir::Pat) -> bool {
 
 /// Call `it` on every "binding" in a pattern, e.g., on `a` in
 /// `match foo() { Some(a) => (), None => () }`
-pub fn pat_bindings<I>(dm: &DefMap, pat: &hir::Pat, mut it: I) where
+pub fn pat_bindings<I>(dm: &RefCell<DefMap>, pat: &hir::Pat, mut it: I) where
     I: FnMut(hir::BindingMode, ast::NodeId, Span, &Spanned<ast::Name>),
 {
     walk_pat(pat, |p| {
         match p.node {
-          hir::PatIdent(binding_mode, ref pth, _) if pat_is_binding(dm, p) => {
+          hir::PatIdent(binding_mode, ref pth, _) if pat_is_binding(&dm.borrow(), p) => {
             it(binding_mode, p.id, p.span, &respan(pth.span, pth.node.name));
           }
           _ => {}
@@ -122,12 +124,12 @@ pub fn pat_bindings<I>(dm: &DefMap, pat: &hir::Pat, mut it: I) where
     });
 }
 
-pub fn pat_bindings_hygienic<I>(dm: &DefMap, pat: &hir::Pat, mut it: I) where
+pub fn pat_bindings_hygienic<I>(dm: &RefCell<DefMap>, pat: &hir::Pat, mut it: I) where
     I: FnMut(hir::BindingMode, ast::NodeId, Span, &Spanned<ast::Ident>),
 {
     walk_pat(pat, |p| {
         match p.node {
-          hir::PatIdent(binding_mode, ref pth, _) if pat_is_binding(dm, p) => {
+          hir::PatIdent(binding_mode, ref pth, _) if pat_is_binding(&dm.borrow(), p) => {
             it(binding_mode, p.id, p.span, &respan(pth.span, pth.node));
           }
           _ => {}
@@ -153,7 +155,7 @@ pub fn pat_contains_bindings(dm: &DefMap, pat: &hir::Pat) -> bool {
 
 /// Checks if the pattern contains any `ref` or `ref mut` bindings,
 /// and if yes wether its containing mutable ones or just immutables ones.
-pub fn pat_contains_ref_binding(dm: &DefMap, pat: &hir::Pat) -> Option<hir::Mutability> {
+pub fn pat_contains_ref_binding(dm: &RefCell<DefMap>, pat: &hir::Pat) -> Option<hir::Mutability> {
     let mut result = None;
     pat_bindings(dm, pat, |mode, _, _, _| {
         match mode {
@@ -172,7 +174,7 @@ pub fn pat_contains_ref_binding(dm: &DefMap, pat: &hir::Pat) -> Option<hir::Muta
 
 /// Checks if the patterns for this arm contain any `ref` or `ref mut`
 /// bindings, and if yes wether its containing mutable ones or just immutables ones.
-pub fn arm_contains_ref_binding(dm: &DefMap, arm: &hir::Arm) -> Option<hir::Mutability> {
+pub fn arm_contains_ref_binding(dm: &RefCell<DefMap>, arm: &hir::Arm) -> Option<hir::Mutability> {
     arm.pats.iter()
             .filter_map(|pat| pat_contains_ref_binding(dm, pat))
             .max_by(|m| match *m {
@@ -226,7 +228,7 @@ pub fn necessary_variants(dm: &DefMap, pat: &hir::Pat) -> Vec<DefId> {
             hir::PatEnum(_, _) |
             hir::PatIdent(_, _, None) |
             hir::PatStruct(..) => {
-                match dm.borrow().get(&p.id) {
+                match dm.get(&p.id) {
                     Some(&PathResolution { base_def: DefVariant(_, id, _), .. }) => {
                         variants.push(id);
                     }

src/librustc/middle/resolve_lifetime.rs

@@ -205,7 +205,7 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
             hir::TyPath(None, ref path) => {
                 // if this path references a trait, then this will resolve to
                 // a trait ref, which introduces a binding scope.
-                match self.def_map.borrow().get(&ty.id).map(|d| (d.base_def, d.depth)) {
+                match self.def_map.get(&ty.id).map(|d| (d.base_def, d.depth)) {
                     Some((def::DefTrait(..), 0)) => {
                         self.with(LateScope(&Vec::new(), self.scope), |_, this| {
                             this.visit_path(path, ty.id);

src/librustc/middle/ty/context.rs

@@ -228,7 +228,7 @@ pub struct ctxt<'tcx> {
     pub types: CommonTypes<'tcx>,
 
     pub sess: &'tcx Session,
-    pub def_map: DefMap,
+    pub def_map: RefCell<DefMap>,
 
     pub named_region_map: resolve_lifetime::NamedRegionMap,
 
@@ -453,7 +453,7 @@ impl<'tcx> ctxt<'tcx> {
     /// reference to the context, to allow formatting values that need it.
     pub fn create_and_enter<F, R>(s: &'tcx Session,
                                  arenas: &'tcx CtxtArenas<'tcx>,
-                                 def_map: DefMap,
+                                 def_map: RefCell<DefMap>,
                                  named_region_map: resolve_lifetime::NamedRegionMap,
                                  map: ast_map::Map<'tcx>,
                                  freevars: FreevarMap,

src/librustc_driver/driver.rs

@@ -700,8 +700,8 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
         syntax::ext::mtwt::clear_tables();
     }
 
-    let named_region_map = time(time_passes, "lifetime resolution",
-                                || middle::resolve_lifetime::krate(sess, krate, &def_map));
+    let named_region_map = time(time_passes, "lifetime resolution", ||
+                                middle::resolve_lifetime::krate(sess, krate, &def_map.borrow()));
 
     time(time_passes, "looking for entry point",
          || middle::entry::find_entry_point(sess, &ast_map));
@@ -718,7 +718,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
          middle::check_loop::check_crate(sess, krate));
 
     time(time_passes, "static item recursion checking", ||
-         middle::check_static_recursion::check_crate(sess, krate, &def_map, &ast_map));
+         middle::check_static_recursion::check_crate(sess, krate, &def_map.borrow(), &ast_map));
 
     ty::ctxt::create_and_enter(sess,
                                arenas,

src/librustc_driver/test.rs

@@ -134,7 +134,7 @@ fn test_env<F>(source_string: &str,
     let lang_items = lang_items::collect_language_items(&sess, &ast_map);
     let resolve::CrateMap { def_map, freevars, .. } =
         resolve::resolve_crate(&sess, &ast_map, resolve::MakeGlobMap::No);
-    let named_region_map = resolve_lifetime::krate(&sess, krate, &def_map);
+    let named_region_map = resolve_lifetime::krate(&sess, krate, &def_map.borrow());
     let region_map = region::resolve_crate(&sess, krate);
     ty::ctxt::create_and_enter(&sess,
                                &arenas,

src/librustc_mir/hair/cx/pattern.rs

@@ -155,7 +155,7 @@ impl<'tcx> Mirror<'tcx> for PatNode<'tcx> {
             },
 
             hir::PatEnum(..) | hir::PatIdent(..) | hir::PatQPath(..)
-                if pat_is_resolved_const(&cx.tcx.def_map, self.pat) =>
+                if pat_is_resolved_const(&cx.tcx.def_map.borrow(), self.pat) =>
             {
                 let def = cx.tcx.def_map.borrow().get(&self.pat.id).unwrap().full_def();
                 match def {
@@ -231,7 +231,7 @@ impl<'tcx> Mirror<'tcx> for PatNode<'tcx> {
             }
 
             hir::PatIdent(bm, ref ident, ref sub)
-                if pat_is_binding(&cx.tcx.def_map, self.pat) =>
+                if pat_is_binding(&cx.tcx.def_map.borrow(), self.pat) =>
             {
                 let id = match self.binding_map {
                     None => self.pat.id,

src/librustc_resolve/lib.rs

@@ -1150,7 +1150,7 @@ pub struct Resolver<'a, 'tcx:'a> {
     // The idents for the primitive types.
     primitive_type_table: PrimitiveTypeTable,
 
-    def_map: DefMap,
+    def_map: RefCell<DefMap>,
     freevars: FreevarMap,
     freevars_seen: NodeMap<NodeMap<usize>>,
     export_map: ExportMap,
@@ -4026,7 +4026,7 @@ fn module_to_string(module: &Module) -> String {
 
 
 pub struct CrateMap {
-    pub def_map: DefMap,
+    pub def_map: RefCell<DefMap>,
     pub freevars: FreevarMap,
     pub export_map: ExportMap,
     pub trait_map: TraitMap,

src/librustc_trans/trans/_match.rs

@@ -222,6 +222,7 @@ use util::nodemap::FnvHashMap;
 use util::ppaux;
 
 use std;
+use std::cell::RefCell;
 use std::cmp::Ordering;
 use std::fmt;
 use std::rc::Rc;
@@ -495,7 +496,7 @@ fn expand_nested_bindings<'a, 'p, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 }
 
 fn enter_match<'a, 'b, 'p, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
-                                          dm: &DefMap,
+                                          dm: &RefCell<DefMap>,
                                           m: &[Match<'a, 'p, 'blk, 'tcx>],
                                           col: usize,
                                           val: MatchInput,
@@ -516,7 +517,7 @@ fn enter_match<'a, 'b, 'p, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
             let mut bound_ptrs = br.bound_ptrs.clone();
             match this.node {
                 hir::PatIdent(_, ref path, None) => {
-                    if pat_is_binding(dm, &*this) {
+                    if pat_is_binding(&dm.borrow(), &*this) {
                         bound_ptrs.push((path.node.name, val.val));
                     }
                 }
@@ -541,7 +542,7 @@ fn enter_match<'a, 'b, 'p, 'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
 }
 
 fn enter_default<'a, 'p, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
-                                     dm: &DefMap,
+                                     dm: &RefCell<DefMap>,
                                      m: &[Match<'a, 'p, 'blk, 'tcx>],
                                      col: usize,
                                      val: MatchInput)
@@ -555,7 +556,7 @@ fn enter_default<'a, 'p, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 
     // Collect all of the matches that can match against anything.
     enter_match(bcx, dm, m, col, val, |pats| {
-        if pat_is_binding_or_wild(dm, &*pats[col]) {
+        if pat_is_binding_or_wild(&dm.borrow(), &*pats[col]) {
             let mut r = pats[..col].to_vec();
             r.push_all(&pats[col + 1..]);
             Some(r)
@@ -596,7 +597,7 @@ fn enter_default<'a, 'p, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 fn enter_opt<'a, 'p, 'blk, 'tcx>(
              bcx: Block<'blk, 'tcx>,
              _: ast::NodeId,
-             dm: &DefMap,
+             dm: &RefCell<DefMap>,
              m: &[Match<'a, 'p, 'blk, 'tcx>],
              opt: &Opt,
              col: usize,
@@ -842,11 +843,11 @@ impl FailureHandler {
     }
 }
 
-fn pick_column_to_specialize(def_map: &DefMap, m: &[Match]) -> Option<usize> {
-    fn pat_score(def_map: &DefMap, pat: &hir::Pat) -> usize {
+fn pick_column_to_specialize(def_map: &RefCell<DefMap>, m: &[Match]) -> Option<usize> {
+    fn pat_score(def_map: &RefCell<DefMap>, pat: &hir::Pat) -> usize {
         match pat.node {
             hir::PatIdent(_, _, Some(ref inner)) => pat_score(def_map, &**inner),
-            _ if pat_is_refutable(def_map, pat) => 1,
+            _ if pat_is_refutable(&def_map.borrow(), pat) => 1,
             _ => 0
         }
     }
@@ -1800,7 +1801,7 @@ pub fn bind_irrefutable_pat<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     let ccx = bcx.ccx();
     match pat.node {
         hir::PatIdent(pat_binding_mode, ref path1, ref inner) => {
-            if pat_is_binding(&tcx.def_map, &*pat) {
+            if pat_is_binding(&tcx.def_map.borrow(), &*pat) {
                 // Allocate the stack slot where the value of this
                 // binding will live and place it into the appropriate
                 // map.

src/librustc_trans/trans/debuginfo/create_scope_map.rs

@@ -167,7 +167,7 @@ fn walk_pattern(cx: &CrateContext,
 
             // Check if this is a binding. If so we need to put it on the
             // scope stack and maybe introduce an artificial scope
-            if pat_util::pat_is_binding(def_map, &*pat) {
+            if pat_util::pat_is_binding(&def_map.borrow(), &*pat) {
 
                 let name = path1.node.name;